With the above modified waveform, one is able to test the amplitude birefringent effect induced by \(({\cal G}_1 k/a)^{\prime }\)  by comparing the modified waveform with the GW strain data from the GW detectors. By performing the Bayesian parameter estimation on the twelve LIGO-Virgo O1/O2 events with the above modified waveform, the amplitude birefringent effect included parity violation has been constrained, which leads to a combined lower bund on the corresponding energy scale \(M_{\rm PV}\)  to be [1]}, [2]}
\(M_{\rm PV} \gtrsim 10^{-22}\; {\rm GeV},\) 
